Apparatus for working strand coverings



Dec. 8, 1931. w. M. HILL ET AL 1,835,597

APPARATUS FOR WORKING STRAND COVERINGS Filed Jan. 1, 1930 2 Sheets-Sheet l Dec. 8, 1931. w. M. HILL ET AL APPARATUS FOR WORKING STRAND COVERINGS l, 1930' 2 Sheets-Sheet Filed Jan.

Patented Dec. 8,1931

@ UNITED'STATES PATENT oFricE wanna n, HILL, or cmcaeo, m nonmr E. ucrannmjor La cannon, rumors,

assrcnons 'ro wns'ri-mn anaemic courm, mcoarona'mn, or NEW YORK, n. Y.,

a coaroaa'non ormw YORK APPA BA'I'US'FOB WORKING STRAND OOVERIKGS Application filed January 1,

This invention relates to apparatus for working strand coverings, and more particu larly to apparatus for slitting a common covering of and removing the individual insulation from theends of parallelly arranged electrical conductors. v This invention has been found particularly useful in preparing the ends of individually insulated, parallelly arranged electrical conductors sheathed in a common braided covering so-that they may be connected to associated electrical apparatus or circuits. vH'eretofore in some instances this has been accomplished by manually slitting in a longitudinal direction the braided covering intermediate the two insulated conductors for a suitable distance from their ends with a hand knife and thereafter laterally severing the braided covering and insulation by the same means at an intermediate point, and then stripping thecovering and the individual insulations from the conductors by means of pliers.

The primary object of this invention is to provide an apparatus for accurately slitting a common-covering of and removing individual insulation from the ends of p'arallelly arranged electrical conductors in a facile manner;

In accordance with one embodiment of this invention there is provided a pair of opposed manually driven'rolls provided with 000 rating peripheral grooves of a predetermined length for receiving therebetween a sheathed pair pf individually insulated parallelly arranged electrical conductors, the grooves being'substantigaelly spanned throu hout their length by op o knives carried hy the rolls for slitting t e sheath'at diametrically opposite sides for a predetermined length as the Ezir of conductors are advanced theretween. Following the slitting operation opposed serrated peripheral portions'of the rolls advance theconductors between and be- 0nd two opposed, spri pressed ivoted I nives to a redetennin point. T e'conductors are t en retracted by a reverse movement of the rolls by the opposed serrated plelripheral portions thereof, whereupon the ives become effective forcutting laterally 1830. Serial No. 417,888.

through the sheath-and the insulation of the individual conductors at a predetermined point intermediate the length of the slitted portion of the sheath, the continued retraction of the conductors stripping the laterally Fig. 2 is a fragmentary side view thereof with a portion of ahousing for the apparatus removed to show the initlal position of the Y conductors before the operation of the appa ratus; i

Fig. 3 is a transverse section. taken on the line 3-3 of Fig. 2; p

Fi 4 is an enlarged fragmentary vertical detai section through the rolls, showing the relative positions of the knives carried by the rolls and the conductors during the sheath. slitting'operation, A

Fi 5 is a vertical detail section taken on the line 55 of Fig. 3, showing the conductors in their completely advanced position between the rolls and before the retraction thereof to laterally sever the covering and in: sulation and the subsequent stripping thereoffrom the conductors;

Fig-6 is'an enlarged fragmentary. detail.

'ew of the op osed. spring-pressed pivotal Ziltting and stripping knives, looking in' the direction in which the conductors are adi t n1" (1 f 1 ig. is an e arge ra entary 'p an view of a pair of sheathed an i l isulated conductors after. their ends have been operated v upon by the apparatus ofthis invention, and Fig. 8 is an enlarged vertigal sectional view taken on the line 8-8 of Fig. 7.

Referr' now to the drawings indetail wherein liEe similar parts tli-rou bout the several views, and'particularly to ig. 2, there is provided reference numerals designate;

'aliousing 10 having base lugs 11 for securing 10'.

the housin to a bench surface or other support. Wit in the housing is journaled a pair of shafts 12 and 13, each having keyed thereto a gear 14 and a roll 15 (Fig. 1), the gears being similar and intermeshing and the rolls being arranged in opposed cooperating relationship, with their adjacent peripheral surfaces slightly spaced apart, as clearly shown in Fig. 2. The lower shaft 13 extends for a distance outside the wall of the housing 10 and has fixed thereto a hand crank 19, which in the normal position of the apparatus lies substantially in a horizontal position, as clearly shown in Fig. 2, and rests against a stop pin mounted in a lug integral with the housing 10. It will be apparent that by moving the crank 19 counterclockwise to the dotted outline position the rolls 15 will be rotatedat the same speed in opposite directions and for identical distances by means of 3 the similar intermeshing gears 14. The.

40. i I the slitting, severing and stripping operamovement of the crank counterclockwise is limited by a stop pin 21 mounted in a manner similar to that of the stop pin 20.

The rolls 15 are arranged in the same vertical plane and are similar in construction, except one is left hand and the other right hand, so that a description of one of the rolls will apply to both. A curved pocket 22 is formed in .the forward side face of the roll 15 extending inwardly from the peripher thereof and therearound for a distance substantially equal to the length of a slit 23 to be formed in a common braided sheath 24 covering a pair of parallelly disposed electrical conductors 25, each having an individual rubber sheath 26, as clearly shown in Figs. 7 and 8. Although the eonductors25 are described and illustrated as being individually insulated, it will be obvious that tions to be presently described may be performed equally well with the apparatus of this invention uponconductors insulated with a common insulating sheath. Secured by screws 28 to the roll 15 within the pocket 22is a plate 29 which substantially fills the pocket and is flush at its outer edge with the periphery of the roll along the length of the pocket (Figs. 2, 3 and '4) The inner peripheral edge and surface of the plate 29 and the corresponding edge and surface ofthe roll 15 along the length of the pocket and for a predetermineddistance from one end thereof are provided with complementary grooves 31 which with the corresponding grooves in the opposed roll 15 cooperate to grip and advance the covered-eonductors 25 'during the operation of the apparatus (Fig. 4). As indicated at 32 in Fig. 2, whenthe ap- ,paratu'sis in its normal position, one end of the grooves 31 terminate on a line substantially joining the axes of the rolls 15.

Clamped between the opposed surfaces of the pocket 22 and the plate 29 is a knife blade 35 (Figs. 3 and 4), the outer cutting edge of the blade lying slightly within the periphery of the roll 15 and the plate 29, as clearly shown in Fig. 4. Duringthe operation of the apparatus. the opposed knife blades 35 carried by the rolls 15 span the distance between the opposed grooves 31 of the rolls sufiiciently to cut through the braided sheath 24 upon opposite sides thereof, but do not cut into the insulation 26 of the conductors 25.

The peripheral surface of the rolls 15 for a the conductors 25 as they are advanced by the rolls 15 and pivoted upon the portion 37 in opposed relation ina vertical plane are a pair of knife blades 38 (Figs. 2, 5 and 6), the opposed cutting ends of which normally are in the path of the conductors 25 as they are advanced through an aperture 39 (Fig. 5) substantially the size and shape of the covered conductors, by-the cooperating rolls.15. Suitably mounted compression springs 42 pressing against the inner ends of the knife blades 38 hold them in their normal position with their cutting ends. which are grooved as indicated at 43 (Fig. 6) sufiiciently spaced from each other to prevent cutting into the metalconductors- 25 during the operation of the apparatus. The movement of the knife blades 38 inwardly by the springs 42 is limited by adjustable stop screws 44 engaging. the knife blades in opposed relation to the springs.

a depressed apertured portion 37 coaxial with The forward wall of the housing 10 intermediate the axes of the shafts 12 and 13 is provided with a hinged cover 45 for the purits inner end 52 are substantially the size and shape of the covered conductors 25, the greatest dimension thereof extending horizontally and coaxially aligned with the opposed grooves 31 in the rolls 15.

In the operation of the apparatus the hand crank 19 should be in its lowered normal position as shown in Fig. 2 and againstthe stop pin 20, thus positioning the ends 32 of the opposed grooves 31 of the rolls 15 substantially in a plane coinciding with the axes f the rolls as hereinbefore described. The

operator then inserts the end of the covered parallel conductors 25 which .are to be slit and stripped into the nozzle 51 with the greatest width of the conductors positioned with suflicient pressure to wedgethe ends 44 fairly tight therebetween, as clearly illustrated in Fig. 2.

The hand crank 19 is then rocked counterclockwise until it comes to a stop against the stop pin 21, as shown fragmentarily in dotted outline (Fig. 2). During this movement of the hand crank 19 it will be apparent from the description hereinbefore given that the rolls 15 will rotate in opposite directions with their adjacent peripheral surfaces, which are slightly spaced apart, moving towards the left (Fig. 2). Due to the cooperating pressure of the opposite side surfaces of the op posed grooves 31 of the rolls 15 upon the covered conductors 25 (Fig. the conductors'will be advanced a pre etermined dis;-

tance towards the left through the aperture 39 in the depressed portion 37 of the left hand wall of the housing 10 into engagement with the opposed'cutting edges of the pivotal spring pressed knife blades 38 which swing outwardly, as clearly shown in Fig. 5. At the end of the movement of the conductors 25 the ends thereof-are spaced from the cutting edges of-the lmife blades 38 a predetermined distance, as' shown in Fig: 5..

This is the length of the covering 24 and the insulation 26 which is to be stripped from the conductors 25 when the conductors are retracted, which operation will'be presently described. Y

Simultaneously with the, advance of the conductors25, as just described, the knife blades 35 carried by the opposed rolls 15 which are engaged with the braided covering 24 at diametrically opposite points thereof I and slit it longitudinally for a predetermined I length beginning at theend of theconduc- .tors. Near the end of the advance of the conductors 25 by the cooperating grooves 31 of .the rolls 15 the opposed serrated peripheral surfaces 36 of the rolls engage the braided covering 24 and continue the advance of the conductors to the position shown in Fig. 5

to the left of the cutting ends of the knife blades 38.

The hand crank'19 is then-moved clockwise back to its normal position in one continuous operation, which immediately sets the rolls 15 in reverse motion to'retract the conductors 25 from between the pivotal 1 spring pressed knife blades 38, the opposed serrated surfaces 36 serving firmly to grip the conductors so that they will ositively be drawn back. This movement o the conductors 25, it will be obvious, causes the cutting edges of the opposed knife blades 38 to catch in the braided sheath 24, facilitated by the pressure of-the springs 42,.and as the conductors continue to move back the blades will rock about their pivots until their cutting edges reach their normal position,- as shown In this latter position of the knife blades 38 the common braided covering 24 and the individual insulation 26 have been severed completely around the conductors 25, except possibly for a very minute thickness, due to a horizontal clearance indicated .at 53 '(Fig. 6) provided between the cutting edges of the blades to prevent the blades from cutting or inarring the metal conductors. The continued movement of the covered parallel conductors 25 still gripped between theserrated surfaces 36 of the moving rolls 15 breaks any unsevered portion-of the covering 24 and the insulation 26 and strips the severed strip of covering and insulation as a wholefrom the conductors and the severed strip of covering and insulation falls from the ends of the conductars and may be caught in a receptacle (not shown). The conductors 25 are then removed manually from between the rolls 15 through the nozzle 51, the strippedends of the conductors appearing as shown in Fig. 7 with a suitable length thereof beginning at the ends bared of all braided covering and insulation and the covering slit upon opposite sides between the insulated conductors for a suitable length from the inner end of the bared portion of the conductors, for'facilitating the connecting thereof to electrical apparatus or circuits. a

It will be understood that by substituting other sets of rolls 15 having difi'erently formed peripheral grooves 31 and correspondingly different associated severing blades 38 and carrying slitting blades 35 and serrated peripheral surfaces 36 of varying lengths a widevrange of conductors of different diameters with different lengths of covering and insulation to be slitted, severed and stripped therefrom may be produced.

Although the invention as herein illustrated and described is particularly well adapted for use in connection wit-h the slitting, severing andstripping of coverings and insulation of electrical conductors, it should v 1. In apparatus for working strand cover- I ings, means for advancing and retracting a plurality of strands having a common cover- 1 ing, means eifective during the vadvancement of. the strands for longitudinally slitting the covering for a predetermined length, and

severing means engaged by the covered strands during their advancement effective upon a retraction of the strands for laterally severing the slitted portion of the covering advanced past the severing means and stripping it from the strands.

2. In apparatus for working strand coverings, means for longitudinally advancing and retracting a plurality of strands having a common covering, means effective during the advancement of the strands for longitudinally slittin the covering for a predetermined length, and severing means engaged by the covered strands during their advancement effective upon a retraction of the strands for laterally severing the covering at a predetermined point along the length of the slitted portion thereof and stripping the sevcred portion of the covering from the strands.

3. In apparatus for working electrical conductor coverings, opposed movable members for longitudinally advancing and retracting for predetermined distances a plurality of individually insulated parallelly arranged conductors having a connnon covering, means controlled by the conductor advancing means during the advancement of the conductors for longitudinally slitting the covering for a pre-, determined length, opposed movable knife blades disposed in the path of the conductors and movable thereby to positions upon opposite points of the covered conductors as the conductors advance thereby and effective upon a retraction of the conductors for laterally severing. the slitted portion of the covering advanced past the knife blades together with a corresponding length of the individual insulation upon the conductors and stripping the whole therefrom, and means for operating the movable members.

4. In apparatus for working electrical conductor coverings, opposed rolls provided with aligned peripheral grooves and serrated ortions for longitudinally advancing an retracting a plurality of individually insulated parallelly arranged conductors having a common covering, aligned knife blades carried by the rolls substantially spanning the grooves thereof and extending for a predetermined distance therealong. for longitudinally slitting the covering upon opposite sides for a predetermined length during the as 'pdvancement of the conductors by the grooves,

the cooperating serrated portions then being effective to continue the advance, opposed pivotal sprin pressed aligned knife blades disposed in t e path of the conductors and movable thereby to (positions upon opposite points of the covere conductors as t e conductors advance thereby and effective upon a retraction of the conductors for laterally severing the slitted portion of the covering advanced past the knife blades together with a corresponding length of the individual insulation upon the conductors and stripping the whole therefrom, and means for simultaneously rotating the rolls at the same speed in opposite directions and for identical predetermined distances during the advancement and retraction, respectively, of the conductors. v

v 5. In an apparatus for removing strand In witness whereof, we hereunto subscribe our names this 20th day of December A. I), 1929.

WALTER M. HILL. ROBERT E. MCFARLAND 

